Numerous so-called low carbohydrate low calorie or light beers have recently been introduced to the market. It is believed that certain of these may be made by a process similar to the process described in Gablinger U.S. Pat. No. 3,379,534. The Gablinger process involves adding the enzyme, amyloglucosidase, to the materials being brewed during the mash and/or fermentation period, in order to split a portion of the dextrins which would otherwise remain in the final beer. The Gablinger patent states that the alpha and beta amylases, which are the enzymes provided by the barley malt used in brewing, cannot provide any of the features of his invention.
Manufacture of diabetic or low sugar beer is also known. Distler U.S. Pat. No. 2,223,444 relates to the production of low sugar beer by boiling the mash and the hopped wort in vacuum at a low temperature so as to preserve the enzyme complex of the malt. Temperatures of 64.degree.-66.degree. C. are not exceeded. This process requires special equipment and procedures not normally used in a brewery. Also considerable time (up to three months) is required until the desired degree of fermentation is reached.
Schimpf U.S. Pat. No. 3,852,495 concerns the manufacture of dietary or diabetic beer of low alcohol and low carbohydrate content and a low calorie value by boiling off alcohol after a first fermentation and then adding additional yeast and a solution of diastase extracted from malt to the partially fermented mixture. This process requires many additional steps not conventionally used in a brewery.
Pauls U.S. Pat. No. 2,782,147 relates to a special beer of high alcoholic content and low extractive matter (carbohydrates) content. Pauls uses special materials and a two stage fermentation with diatase added at the start of the main fermentation and again at the completion of the main fermentation. Additional diastase extract and yeast can be added during storage. The Pauls process requires special malt, hops, yeast and water. The Pauls patent does not disclose the details of his method for preparing the diatase extract.
Thomas U.S. Pat. No. 2,146,240 also shows a special diatetic and dietary beer made by a double fermentation. The main fermentation uses Saccharomyces cerevisiae and the secondary fermentation uses a yeast which ferments the dextrins such as, Schizosaccharomyces pombe or Saccharomyces thermantitonum.
Gluek U.S. Pat. No. 3,373,040 shows the production of malt liquor products of low protein, sugar, and real extract contents. The process consists of preparing separately a cooker mash of malt cereal products and water and a main mash and heating the main mash at 42.degree.-45.degree. R. A small portion of the liquid from the main mash is removed and some of this is added to the boiled hopped wort during cooling and the remainder is added during fermentation. As a final step, the fermented liquid is diluted and treated with emulsifiers, hop extract, foam builder and liquid chillproof.
None of the prior processes results in a naturally and conventionally brewed beer of the type contemplated by this invention.
Accordingly, it is a principal object of this application to provide a process for producing a naturally and conventionally brewed beer which is low in carbohydrates and calories. It is a further object to provide such a process using only materials commonly used in a brewing process. Still a further object is to provide a process for brewing low calorie, low carbohydrate beer which uses regular equipment normally found in a brewing plant and results in a process substantially free of contaminating microorganisms. These and other objects and advantages will become apparent hereinafter.
This invention comprises a process for brewing a light type beer comprising separate mashing of a portion of malt at temperatures which substantially inactivate the microorganisms of the malt without deactivating the enzymes, and adding this mash to the wort during or before fermentation. The invention further comprises the products and processes hereinafter described and claimed.